u-boot/arch/x86/include/asm/mrccache.h

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/*
* Copyright (C) 2014 Google, Inc
* Copyright (C) 2015 Bin Meng <bmeng.cn@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _ASM_MRCCACHE_H
#define _ASM_MRCCACHE_H
#define MRC_DATA_ALIGN 0x1000
#define MRC_DATA_SIGNATURE (('M' << 0) | ('R' << 8) | \
('C' << 16) | ('D'<<24))
#define MRC_DATA_HEADER_SIZE 32
struct __packed mrc_data_container {
u32 signature; /* "MRCD" */
u32 data_size; /* Size of the 'data' field */
u32 checksum; /* IP style checksum */
u32 reserved; /* For header alignment */
u8 data[0]; /* Variable size, platform/run time dependent */
};
struct mrc_region {
u32 base;
u32 offset;
u32 length;
};
struct udevice;
/**
* mrccache_find_current() - find the latest MRC cache record
*
* This searches the MRC cache region looking for the latest record to use
* for setting up SDRAM
*
* @entry: Position and size of MRC cache in SPI flash
* @return pointer to latest record, or NULL if none
*/
struct mrc_data_container *mrccache_find_current(struct mrc_region *entry);
/**
* mrccache_update() - update the MRC cache with a new record
*
* This writes a new record to the end of the MRC cache region. If the new
* record is the same as the latest record then the write is skipped
*
* @sf: SPI flash to write to
* @entry: Position and size of MRC cache in SPI flash
* @cur: Record to write
* @return 0 if updated, -EEXIST if the record is the same as the latest
* record, -EINVAL if the record is not valid, other error if SPI write failed
*/
int mrccache_update(struct udevice *sf, struct mrc_region *entry,
struct mrc_data_container *cur);
/**
* mrccache_reserve() - reserve MRC data on the stack
*
* This copies MRC data pointed by gd->arch.mrc_output to a new place on the
* stack with length gd->arch.mrc_output_len, and updates gd->arch.mrc_output
* to point to the new place once the migration is done.
*
* This routine should be called by reserve_arch() before U-Boot is relocated
* when MRC cache is enabled.
*
* @return 0 always
*/
int mrccache_reserve(void);
/**
* mrccache_get_region() - get MRC region on the SPI flash
*
* This gets MRC region whose offset and size are described in the device tree
* as a subnode to the SPI flash. If a non-NULL device pointer is supplied,
* this also probes the SPI flash device and returns its device pointer for
* the caller to use later.
*
* Be careful when calling this routine with a non-NULL device pointer:
* - driver model initialization must be complete
* - calling in the pre-relocation phase may bring some side effects during
* the SPI flash device probe (eg: for SPI controllers on a PCI bus, it
* triggers PCI bus enumeration during which insufficient memory issue
* might be exposed and it causes subsequent SPI flash probe fails).
*
* @devp: Returns pointer to the SPI flash device
* @entry: Position and size of MRC cache in SPI flash
* @return 0 if success, -ENOENT if SPI flash node does not exist in the
* device tree, -EPERM if MRC region subnode does not exist in the device
* tree, -EINVAL if MRC region properties format is incorrect, other error
* if SPI flash probe failed.
*/
int mrccache_get_region(struct udevice **devp, struct mrc_region *entry);
/**
* mrccache_save() - save MRC data to the SPI flash
*
* This saves MRC data stored previously by gd->arch.mrc_output to a proper
* place within the MRC region on the SPI flash.
*
* @return 0 if saved to SPI flash successfully, other error if failed
*/
int mrccache_save(void);
#endif /* _ASM_MRCCACHE_H */